The present invention concerns a tool for proper positioning of a guide pin within the head and neck portions of a femur, said pin for subsequent guidance of a hip nail prosthesis.
Conventional practice in the installation of a hip nail entails, briefly, the initial insertion of a guide pin through the upper end of the femur, the femoral neck and into the femoral head. AP and lateral X-rays are taken normally to verify guide pin location. Should repositioning of the pin be required, the corrections are plotted on the X-rays and a second guide pin insertion made. Typically both guide pin insertions are made without the aid of any guide, with the surgeon relying solely on unaided judgment. My U.S. Pat. No. 3,945,377 disclosed a hip pinning tool directed toward providing a reference or guide for both the guide pin and subsequently installed hip nail.
Complicating hip nail installation is the angulation of the femur neck and head, with respect to the femoral shaft, which angulation varies between individuals. Such variances are often accentuated by reason of neck and head displacement from injury which further complicate the task of nail installation. Presently, proper nail placement within a damaged femur is largely dependent upon the unaided skill and judgment of the surgeon. Improperly positioned hip nails, needless to say, result in further complications for both patient and surgeon.
Some tools, heretofore proposed, do not provide a reference point offset from the femur and stationary therewith. Such tools are often in supported association with the surgical table or taped to the patient and hence do not avoid discrepancies resulting from shifting of the leg member during an operation.